Metal jacketed gaskets0 pages

Metal jacketed gaskets

Metal jacketed gaskets are proven sealing elements for use
in apparatus construction, which are however increasingly
being replaced at temperatures up to 550 °C by metal/softmaterial gaskets, such as grooved gaskets (see remarks
on the next page).

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At temperatures above 500 °C, such as in hot-blast areas,
metal jacketed gaskets can still hold their own against solid
metal gaskets such as weld ring gaskets.
Jacketed gaskets generally consist of a metal sheet coating
with an insert of RivaTherm Super, graphite or FA1) or some
layers of sheet metal.
The metal sheet coating should be as soft and flexible as
possible, but to prevent corrosion it is often made from a
stainless steel jacket in 1.4541 or 1.4571 steel.
The harder the jacket, the finer the flange roughness needs
to be.

Profile F8

picture 1

Metal jacketed gaskets for heat exchangers are supplied
with partitions in the model shown (picture 1).
Metal jacketed gaskets are also available as frames with
rounded corners.
In flanges with tongue and groove or male and female face
joints the jacketed gaskets should be fitted so that the tongue
and/or the male face is against the smooth side of the gasket (picture 2).

The inlay is selected according to the flange irregularities
that need to be covered. The better the quality and the evenness of the sealing surfaces, the harder the inlay can be.
There is a wide range of possible combinations; the following are extremes at both ends:
very soft:

Coating of aluminium,
inlay of graphite

very hard:

picture 2

Coating of stainless steel,
inlay of mica

Gasket limiting values

Surface pressure
limits for 20 °C

N/mm2

Surface pressure
limits for 300 °C

N/mm2

6,3
12,5

2,5
6,3

6,3
12,5

6,3
12,5

σϑ

30
100

60
150

70
180

100
250

60
180

200
500

σv
σϑ

(40)
(60)

70
120

80
150

115
200

70
150

200
350

Iron
Iron

12,5
25

Iron
Nickel
Graphite

25
50

from
to
σv

Graphite

Iron
Nickel
Graphite

µm

F3L

Copper
Brass
Graphite

Recommended max. roughness
(RZ) of the flange surfaces

Graphite

Aluminium

Materials

FW3
Stainless steel

F2 to F17

Profiles

Kempchen Dichtungstechnik GmbH · Tel. +49 (0)208 8482 0 · Fax. +49 (0)208 8482 285 · info@kempchen.de · www.kempchen.de

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Metal jacketed gaskets

1) Fibre sheets with binder